Technical Field
The present disclosure relates to a position pointer, such as a position pointer for performing a pointing operation and entering text and graphics on a position detector.
Description of the Related Art
A touch input system is known that includes a position detector, a plate-shaped input unit, and a position pointer such as electronic pen or cursor. Depending on the position detector, a simple rod or a human finger may be used as a position pointer. Such an input system is generally called a tablet or digitizer, finding wide application for entering text and illustrations on computers such as personal computers and tablets.
The position detector has a plurality of linear conductors arranged in a matrix form (which may include a loop coil), allowing for the position detector to detect the position of the position pointer on the basis of a voltage that develops or a change thereto as a result of approach of the position pointer.
Various capacitive and electromagnetic mechanisms are known as specific mechanisms for a position detector to detect the position of a position pointer. Capacitive mechanisms take advantage of capacitance that develops between the position pointer and linear conductors in the position detector. Capacitive mechanisms may be subdivided into self-capacitance mechanisms and mutual-capacitance mechanisms. Self-capacitance mechanisms detect a voltage change in each linear conductor. Mutual-capacitance mechanisms detect a change in potential difference between intersecting linear conductors. Self-capacitance mechanisms may be further classified into mechanisms that apply a voltage to the linear conductors from the position detector side and other mechanisms that cause a voltage to develop in the linear conductors by sending a signal from the position pointer. The former may be used when the position pointer is, for example, a finger or other object that cannot send a signal. The latter may be used when the position pointer can send a signal. On the other hand, electromagnetic mechanisms send electromagnetic waves from a position detector to a position pointer by using the linear conductors as a transmission antenna. In response to the electromagnetic waves, the position pointer sends a signal that is received by the position detector by using the linear conductors as a reception antenna. Electromagnetic mechanisms may handle transmission and reception in a time-shared manner.
Patent Document 1 discloses an example of a position pointer, an electronic pen. As described in Patent Document 1, the position pointer, an electronic pen, generally includes a rod-shaped core body, a writing pressure detection section or circuitry, a signal transmission section or circuitry, and a housing. The writing pressure detection section detects a writing pressure based on movement of the core body. The signal transmission section transmits a signal. The housing accommodates the above components. An opening portion is provided at one longitudinal end of the housing to allow a pointing section to protrude.